Suspicious gravel generates in cold ocean ruins and trail ruins — large buried structures found across most biomes that predate the archaeology system's introduction. Visually it is nearly indistinguishable from regular gravel, showing only a faintly speckled surface pattern, so locating it requires either careful visual inspection or prior knowledge of generation sites.

Brushing follows the same mechanic as suspicious sand: hold a brush, right-click repeatedly, and after several strokes the block drops its item and converts to regular gravel. Despite gravel's default behaviour of falling under gravity, suspicious gravel is immune — it stays in place. Mining it without a brush instantly destroys the buried item, leaving only regular gravel.

The loot table varies by structure. Cold ocean ruins yield primarily coal and wheat seeds, while trail ruins offer a far richer pool: pottery sherds from across the full decorative set, sniffer eggs — the only source of that mob outside Sniffer trades — coloured dyes, and emeralds. Suspicious gravel does not regenerate and each block holds exactly one item.